Aircraft and method of operating the same



Oct. 25, 1932. Y J. DE LA CIERVA AIRCRAFT AND METHOD OF OPERATING THE SAME Filed Dec. 20, 1929 2 Sheets-Sheet l INVENTOR W ATTORNEYS Oct. 25, 1932. I DE LA RVA 1,884,596

AIRCRAFT AND METHOD OF OPERATING THE SAIE Filed Dec. 20. 1929 2 Sheets-Sheet 2 INVEN OR BY WT'WW ATTORNEY Patented Oct. 25, 1932 UNITED STATES PATENT OFF-ICE,

JUAN DE LA GIERVA, OI MADRID, SPAIN, ASSiIGNOR TO AUTOGIBO COMPANY- 01 v AMERICA, OF PHILADELPHIA, PENNSYLVANIA, A CORPORATION OF DELAWARE moaarr an!) mnrnon or ornnarme 'rnr. sauna Application filed December 2 0, 1929. Serial No; 415,387.

This invention relates to aircraft and method of operating the same and is especially concerned with the general type of aircraft whichiincludes a movable sustaining wing system such, for example, as a plujects in view, the first of which is the facilitation of the initial starting of the sustaining blades prior to taking off from. the

' ground. The second of these objects will appear more clearly from a consideration of the following remarks.

In common types of air lanes having the usual rigid and non-mova le supporting or sustaining wings, the lift exerted by the wings decreases very quickly and substantially as the angle of incidence thereof increases, positively, beyond approximately 16 which is the usual upper limit for normal flying of aircraft of the rigid wing type. On the other hand, the lift exerted by a rotatably mounted wing system does not decrease materially out of proportion to the increase in the angle of incidence of the general plane of rotation of the sustaining 7 blades, until the angle approaches approximately from the horizontal. In other words, with the fixed-wing type of aircraft the lift decreases much more rapidly than, and out of proportion to, increases in the positive angle of incidence, while, with the type of aircraft having rotatably mounted wings, the lift does not sharply fall off until positive angles of 50 or more are reached. Most types of aircraft, furthermore, are provided with supporting means, usually including an undercarriage located at the forward end of the fuselage and a tail support or skid at the rear end, which are relatively arranged and proportioned to support the aircraft on the ground at a considerable inclination with respect thereto.

However, it is desirable, at least under certain circumstances, that aircraft of the rotative wing-type be capable of support on the ground in such position that the general plane in which the supporting blades or wings revolve (i. e., a plane perpendicular to the axis of the rotative system) is parallel or nearly parallel to the ground. For example, when making a perpendicular or a relatively steep landing, in a substantial wind, if the tail or rear end of the fuselage were permitted to drop sufficiently to materially increase the angle of incidence of the plane perpendicular to the axis of the rotor, the relative airflow created bythe wind might be sufiicient to lift the'machine from the ground again, particularly in view of the fact that the lift exerted by the sustaining blades would not be materially decreased, even at considerable positive angles.

Inorder to positively avoid encountering difficulties of this nature, the present invention contemplates the provision of means for supporting the aircraft on the ground in such position that the rotor axis closely approximates a perpendicular position with respect to the ound.

At t e same time, however, the present invention involves a method of starting such that it is desirable that the aircraft should be capable of support on the ground at a' substantial inclination with respect thereto.

To this end, I have provided the adjustable supporting mechanism described herebelow.

How the foregoing, together with other objects and advantages are obtained, will be apparent from the consideration of the following description taken with the accom panying drawings which illustrate the preferred embodiment of the invention, and m which,

Fig. 1 is a side view of an aircraft of the rotative wing-type to which the improvements of the present invention have been applied and with which the method of'the present invention may be practiced, the view being taken of the aircraft resting on the ground at a substantial inclination with respect thereto;

Fig. 2 is a view similar to Fig: 1 but illustrating the aircraft resting on the ground in such position that the'rotor axis approximates perpendicularity with respect thereto;

Fig. 3 is aside View of a portion of the rear end of the fuselage illustrating the application of the adjustable supporting mechanism thereto, certain of the arts ,being broken away and shown in section for the sake of po absorber 19 is preferably provided. The

clarity;

Fig. 4 is a sectional view taken substantialily as indicated by the line 44 of Fig. 3;

an t Fig. is a' detailed view taken as indicate by the line 5-5 of Fig. 3.

By reference, first, to Figs. 1 and 2, it will be seen that the aircraft illustrated includes a body or fuselage 2 at the forward end of which is arranged the propeller 3 which may be driven by an suitable motor means (not shown) and at t e rear end of which the tail structure is supported, the said tail structure 7 including a horizontally disposed aerofoil surface 4 and a vertically disposed surface 5 which are adapted to be adjusted in the usual manner to control, respectively, the attitude of the aircraft and the direction thereof in flight.

Mounted on the supports 6 at a convenient distance above the fuselage is a set of sustaining blades 7, four being here shown. The mounting of the blades is such as to rmit rotation thereof about a common axis y the action of the relative air-flow when the aircraft is in flight. The blades may be made flexible or ma be flexibly or pivotally mounted in suc manner as to permit them, independentl to assume various positions under the in uence of lift, centrifugal, and other forces, as indicated at a, b.

If desired supplemental supporting or sustainin surfaces 8 may be provided at each side 0 the fuselage and may be employed to support the usual aileron or manually operable lateral stability control surfaces 9.

Structural features of the rotary wing sys.--

tem herein shown only generallyare fully disclosed and claimed inv my copending appli ion Serial No. 496,872, filed November 20, k 30. The combined arrangement of the rotary and fixed win is fully disclosed and claimed in m co n ing application Serial No. 414,901, ed oember 18, 1929.

The machine is'also provided with an undercarria 10 including wheels 11, referably of t e rubber inflated type, an shock absorbers .12. For reasons which will appear more full hereinafter the undercarriage is prefers ly made of relatively great heiglat as compared to'the length of the fusepending from the rear portion of the fuselage 2-1 have su portin or ski mechanism including an i ated w eel 13 which is rotatably mounted .between the lower ends of the members 14,

the upper ends thereof being pivotally coni nected to portions of the framework 15 of the fuselage as indicated at 16 in Figs. 3 and 4. A short distance above the wheel 13 I provided an adjustable tail have arranged the pivot pin 17 extending be tween the members 14 and serving as the pivot point for the lower end of the suprting member or link 18 in which a shock other end of the member 18 extends upwardly into the fuselage and is pivotally connected at 20 to the collar or yoke 21 which is movement along the mounted for slidin fore and aft within the shaft 22 extending fuselage frame between the bracing members 23 and 24 to which its ends 'are secured. A

controlling link 25 extending .rearwardly- 4 tail support is illustrated in full lines in.

Fig. 1, and in this connection it is to be observed that stop means 27 are provided on the fuselage to take the weight of the tail when the machine is at rest on the ground with the tail skid in its retracted position. This preferably comprises a rubber block wh i dh may be suitably supppsrted at the underside of the frame of the. elage' with a suitable backing means 28 as a mounting therefor (see Fig. 5 In retracted position, wind resistance o the tail-supporting structure is also reduced to a minimum.

It is to be understood in connection with the construction of the aircraft, in general, that the undercarriage, the fuselage and the tail support are so relatively proportioned and arranged that, with thetail support in its extended position (full line show in Fig. 2), "the machine may be egg on the ound G with the disc defin b; the sustainmg blades 7, in rotation, at least approximating parallelism or at a s ht incidence with respect to the ound. e undercar-. riage, fuselage and tail support, furthermore, are so arranged and proportioned that, with the tail support in its retracted position (see Fig. 1), the rotor disc extends at a ve substantial inclination rearwardly and downwardly. This position of the aircraft also results in the positioning of the propeller 3 in such' manner that the wash, or at least a portion thereof, is-directed against the ground at is int, or within a zone, such that upondedihtion by the ground, a large portion of the slip stream is caused to pass upwardly and rear-wardly blades. In t is manner, the slip stream 0 slip stream or back the propelling means may be employed for initiating movement of the rotor blades prior to taking off from the ground merely by utilizing the ground to deflect backwash or slip stream through'the rotor blade disc.

In order to obtain the maximum possible deflection by the ground, the undercarriage 10 is preferably made of relatively great height, while the fuselage ispre'ferable relaatively short. A further advantage of .the high undercarriage is that along travel may be provided in the shock-absorbing means to take the thrust of vertical descent. In addition, the tail support is so arranged that it may be drawn up very close to the underside of the fuselage and thus permit support of the aircraft at the maximum possible inclination, for starting purposes.

In conclusion it is to be observed that, in

addition to providing a convenient and effective'method and apparatus for initially starting the rotor blades, the present inven- 'tion provides for support ofthe aircraft on the ground in such manner that landings may safely be made vertically or at steep angles,

even in a relatively strong wind, in viewof the fact that the rotor disc may be so disposed as to its general angle of incidence, by extending the tail support, that the effect of the relative air-flow created by the wind would notincrease the lift sufliciently to preadapted to contact with the ground and movable to a plurality of positions vertically with respect to the aircraft, the body of the said aircraft, the sustaining blades and the supporting means being relatively arranged and proportioned so that, with the said member in a position adjacent the aircraft, at least a portion of the slip stream ofthe propelling means strikes the ground and is deflected thereby upwardly throughth of the sustaining blades,

2. An aircraft including 8 path of travel fuselage, sustaining blades rotatably mounted'above the fuselage for actuation by the relative air-flow in flight, propelling means, an undercarriage and a tail supporting device, .the height of said undercarriage and of said device and the length of the fuselage being so relatively proportioned that, when the aircraft is on the ground, at least a portion of the slip stream of the propelling means. strikes the ground' fuselage for actuation by the relative airflow in flight, propelling means, an undercarriage and a tail supporting device, the height of said undercarriage and of said device and the length of the fuselage being so relatively proportioned that, when the aircraft is on the ground, at least a portion of the slip stream of the propelling means strikes the ground at such point that upon deflection thereby it passes through the path of travel of the sustaining blades, together with means for altering the height of the said device including a connection therefrom to a cockpit of the fuselage.

4. An aircraft including a fuselage, sustaining blades rotatably mountedabove the the undercarriage serve to su port the fuse- I lage in substantiall horizont l the aircraft is on t e ground.

' 5. An aircraft including a fuselage, sustaining blades rotatably mounted above the fuselage for actuation by the relative air-flow in flight, propelling means, an undercarriage and a vertically adjustable tail supporting device, the adjustment of said device including a position in which the device and the underposition when carriage serve to support the fuselage in substantially horizontal position when the aircraft is on the ground and a position in which the device and the undercarriage serve to support the fuselage at an angle such that at leasta portion of the slip stream of the propelling means is directed against the ground at such point-that upon deflection thereby it passes through the path of travel of the sustaining blades. r

6. The method of operating an aircraft of the type having movable sustaining means actuable by relative air-flow, which includes creating an air-flow and utilizing the ground to effect a deflection thereof against said means to move the same.

the type having propelling means and movable sustaining means actuable by relative air-flow, which includes utilizing the ground to eifect a deflection of slip stream of the proa 7 The method of operating an aircraft of v 8. The method of operating an aircraft having -movable sustaining means actuable by relative air-flow, which includes utilizing the ground to deflect air through the path of travel of the sustaining means to initiate movement thereof preparatory to taking off and utilizing the relative air-flow resulting from movement of the aircraft in flight .to I maintain the sustaining means in motion.

9. The method of operating an aircraft havforward pro lling means and rotatably :io unted sustainii ig blades actuable by relative air-flow, which includes starting the propelling means' and utilizing the ound to deflect at least a portion of the slip stream thereof through the path of travel of the sustaining blades to initiate movement thereof.

10. The method of operating an aircraft having forward propelling means and rotatably mounted sustaining blades actuable bg' relative air-flow, which includesstarting t e propelling means, utilizing the ground to deflect at least a portion of the slip stream thereof through the path of travel of the sustaining blades to initiate movement thereof, and utilizing the relative air-flow resulting from movement of the aircraft in flight to maintain the sustaining blades in rotation.

In testimony whereof I have hereunto signed my name.

' JUAN ms: LA CIERVA. 

